Analog Devices Inc. AD7779ACPZ

Overview

AD7779ACPZ from Analog Devices is an 8-channel, 24-bit simultaneous sampling Σ-Δ ADC with per-channel PGA (gains 1/2/4/8), internal 2.5 V reference, and dual operating modes (high resolution: 108 dB SNR at 16 kSPS; low power: 3.37 mW/channel). It supports true differential or single-ended inputs, operates from −40°C to +105°C, and targets precision sensor data acquisition in circuit breakers and EEG systems.

For engineers reviewing the AD7779ACPZ datasheet, AD7779ACPZ pinout, AD7779ACPZ application, or AD7779ACPZ equivalent, key selection considerations include simultaneous 24-bit sampling across eight channels, programmable sample rate converter (SRC) for coherent line-frequency rejection, low input current (±1.5 nA differential), sinc3 filter latency, and integrated 12-bit SAR ADC for diagnostics without sacrificing main channel availability.

Technical Context

The AD7779ACPZ integrates eight independent Σ-Δ modulators with sinc3 digital filters and a dedicated sample rate converter (SRC) enabling fine ODR resolution down to 15.2 µSPS-critical for maintaining coherence with 0.01 Hz line frequency drift. Each channel features a programmable gain amplifier (PGA) and configurable input topology (true differential, pseudo-differential, or single-ended).

Digital control is implemented via dual interfaces: a dedicated high-speed data output interface (DOUTx/DRDY) and a separate SPI port for register configuration, SAR ADC access, and SRC programming. The device includes an on-chip 12-bit SAR ADC with internal multiplexer for chip-level diagnostics and external signal validation using three GPIOs.

Key Specifications

Pinout & Package

The AD7779ACPZ is housed in a 64-lead LFCSP (9 mm × 9 mm, 0.8 mm pitch) with exposed thermal pad. Pin functions are defined per Analog Devices Rev. F datasheet Section "Pin Configuration and Function Descriptions" (pages 14–16).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multichannel high-resolution ADC applications.

Compared with AD7779ACPZ, AD7768-1ACPZ reduces channel count and feature set to lower cost and size, while LTC2500-32IUK#PBF trades configurability and speed for maximum DC resolution-making AD7779ACPZ the optimal choice for synchronized, adaptive, and self-validating 8-channel acquisition.

Availability

AD7779ACPZ is available at Aetrix Electronics and suitable for circuit breaker monitoring, electroencephalography (EEG), and industrial process control requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AD7779ACPZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, founded in 1965 and headquartered in Wilmington, MA.

The AD7779ACPZ belongs to Analog Devices' precision data acquisition portfolio, designed specifically for applications demanding simultaneous high-resolution sampling, low input bias, and integrated diagnostics-such as energy metering, medical instrumentation, and industrial automation.

FAQ

What is the maximum simultaneous sampling rate supported by the AD7779ACPZ?

The AD7779ACPZ supports up to 16 kSPS per channel in high resolution mode and 8 kSPS per channel in low power mode. All eight channels sample simultaneously with matched latency and inter-channel skew <1 ns. This capability is enabled by eight independent Σ-Δ modulators and sinc3 filters, making AD7779ACPZ suitable for phase-sensitive applications like power quality analysis and vibration monitoring where timing coherence across channels is critical.

Does the AD7779ACPZ include an internal voltage reference, and what is its accuracy?

Yes, the AD7779ACPZ integrates a 2.5 V internal reference with ±0.2% initial accuracy at 25°C and a typical temperature coefficient of ±10 ppm/°C. It also supports external reference inputs from 1 V to 3.6 V. The reference buffer can be enabled or disabled to optimize power versus noise performance. This internal reference eliminates the need for external precision references in many applications, simplifying design and reducing BOM cost while maintaining 108 dB SNR in high resolution mode.

How does the sample rate converter (SRC) in the AD7779ACPZ improve measurement coherence?

The SRC in the AD7779ACPZ allows programmable ODR resolution down to 15.2 µSPS, enabling exact integer multiples of line frequencies (e.g., 50 Hz or 60 Hz) to be achieved. This eliminates spectral leakage and improves rejection of power-line interference-especially important in energy metering and EEG applications. The SRC is configured via SPI and operates independently per device, allowing precise synchronization across multiple AD7779ACPZ units in daisy-chain or parallel topologies without external clock synthesis.

Can the AD7779ACPZ perform self-diagnostics without interrupting normal operation?

Yes, the AD7779ACPZ includes a dedicated 12-bit SAR ADC and internal multiplexer that operate independently of the main Σ-Δ channels. This allows continuous monitoring of internal nodes (e.g., VCM, REF, supply rails) and validation of external signal paths using external MUXes controlled via GPIO0–GPIO2. Diagnostics run in background mode, ensuring uninterrupted 24-bit acquisition on all eight channels-critical for functional safety compliance in industrial and medical systems.

What are the power supply requirements for the AD7779ACPZ in high resolution mode?

In high resolution mode, the AD7779ACPZ requires AVDD1x/AVSSx = ±1.65 V (bipolar) or 3.3 V/AGND (unipolar), AVDD2x/AVSSx = 2.2 V–3.6 V, AVDD4/AVSSx = AVDD1x − 0.3 V to AVDD1x, and IOVDD = 1.8 V–3.6 V. Total typical supply current is 22.7 mA on AVDD1x, 9.45 mA on AVDD2x, 2 mA on AVDD4, and 10.7 mA on IOVDD-resulting in ~133 mW total power dissipation at 3.6 V supplies. Low-power mode reduces this to ~44 mW.